Dietary Intake Fell After Pancreatic Surgery Despite Falling Inflammation

Patients recovering from surgery for periampullary malignancies reported substantially lower food and energy intake during the first six months after pancreatoduodenectomy, even as markers of systemic inflammation improved. In a prospective cohort conducted at a public academic center in Southeast Brazil, median reported energy intake fell from 2,625 kilocalories per day before surgery to 2,011 at three months and 1,948 at six months after discharge. The decline, alongside reductions in most macronutrients, fiber, calcium, iron and selenium, persisted alongside clinical improvement rather than signaling a straightforward recovery in nutritional status. The findings were published in Supportive Care in Cancer.

The study followed 24 adults undergoing classic or pylorus-preserving pancreatoduodenectomy for periampullary malignancies. Eighteen patients were reassessed three months after discharge and 16 at six months; the researchers also compared them cross-sectionally with 20 age- and sex-similar controls undergoing upper endoscopy for normal or nonspecific findings. The surgical group was predominantly male, pancreatic adenocarcinoma was the most common diagnosis, and 87.5% met the study’s criteria for cancer cachexia despite having a mean body mass index in the overweight range. Postoperative morbidity was substantial, including delayed gastric emptying and clinically relevant postoperative pancreatic fistula, while suspected or documented pancreatic exocrine insufficiency was common.

Dietary intake was estimated with a 114-item Brazilian Longitudinal Study of Adult Health food frequency questionnaire adapted to cover the preceding 30 days. Frequencies were converted into daily consumption, and nutrient values were derived from the Brazilian Food Composition Table. The investigators calculated an energy surplus by subtracting a clinical reference of 25 kilocalories per kilogram of actual body weight per day from reported intake; this ESPEN-based lower bound was not a measurement of physiological energy expenditure. Median reported energy surplus consequently declined from 1,034 kilocalories per day before surgery to 262 at three months and 289 at six months. Post-discharge energy, lipid and selenium intake were also lower than in the contextual control group.

Systemic inflammation generally moved in the opposite direction. Median C-reactive protein fell from 6.19 milligrams per liter before surgery to 0.40 milligrams per liter at six months, while aspartate aminotransferase and alanine aminotransferase also decreased. Ferritin declined but remained higher than the control value, and hemoglobin showed no detected longitudinal change. These results illustrate why ferritin and hemoglobin cannot be treated as interchangeable measures of iron status: inflammation can influence ferritin, and a falling ferritin concentration did not correspond to a detected change in hemoglobin or the broader iron profile. Albumin-based and composite indices also followed distinct paths rather than moving as a single group.

The Glasgow Prognostic Score and the C-reactive protein-to-albumin ratio decreased, the C-reactive protein–albumin–lymphocyte index increased, and the Prognostic Nutritional Index showed no detected longitudinal change. The first two indices include inflammatory and protein-related components and broadly tracked the reduction in C-reactive protein, whereas the Prognostic Nutritional Index depended on albumin and lymphocyte values and did not register a comparable change. The investigators therefore described these measures as complementary rather than interchangeable. Their results also support multiparametric nutritional assessment: an improvement in one laboratory marker or composite score should not automatically be interpreted as restoration of intake, muscle status or micronutrient adequacy.

Fat-soluble vitamins produced another pattern. Serum vitamin A did not change detectably over time but remained lower than in the contextual controls, while serum vitamin E declined from 7.46 to 5.54 milligrams per liter despite no detected change in reported vitamin E intake. Zinc intake also showed no detected longitudinal change. These findings indicate that what people report eating may not fully represent circulating vitamin status after major pancreatic surgery. The authors noted that pancreatic exocrine dysfunction, fat maldigestion and variable use of pancreatic enzyme replacement therapy may influence fat-soluble vitamin absorption, but the study did not systematically measure fecal elastase-1 or establish enzyme dose adequacy or adherence, so it could not determine whether those factors explained the observed differences.

Exploratory regression analyses found only limited and inconsistent correspondence between diet and biomarkers. Reported iron intake was positively associated with hemoglobin before surgery in models adjusted for either C-reactive protein or ferritin, but this association was not observed after surgery. Protein intake was associated with albumin at six months only in the ferritin-adjusted model. No consistent postoperative relationships appeared for zinc, fat-soluble vitamins or protein, and an inverse association between vitamin E intake and serum vitamin E among controls occurred in only one adjusted model. Because the sample was not powered for these dietary–biomarker analyses, the findings are hypothesis-generating and cannot establish causation. Self-reported food frequency questionnaires also introduce recall error, portion-size misestimation and exposure misclassification, further weakening any interpretation of a simple intake-to-blood-marker relationship.

The cohort’s principal strength was its prospective design, with standardized assessments before surgery and at two postoperative points, a food frequency instrument adapted from a validated Brazilian survey, centralized laboratory assays and multiplicity adjustment for planned comparisons. Its limitations were substantial. The sample size was calculated for the parent cohort’s resting-energy-expenditure outcome, leaving the dietary, biochemical and subgroup analyses underpowered. Attrition was predominantly related to mortality, and missing observations were not imputed because post-death dietary and laboratory values are undefined. Mixed-effects estimates consequently describe patients who remained alive and were available at each follow-up assessment, rather than the entire baseline population. Contextual controls were assessed only once, so they provided cross-sectional context but not a longitudinal counterfactual.

Clinically relevant variables were also incompletely resolved. Suspected or documented pancreatic exocrine insufficiency and exposure to pancreatic enzyme replacement therapy were recorded, but access, adherence, indication and dose adequacy were not protocolized; a low frequency of treatment therefore cannot be interpreted as proof of undertreatment. Small subgroup strata, multiple comparisons and limited capacity for multivariable adjustment further constrained the exploratory analyses, and no clinical subgroup difference remained significant after false-discovery-rate correction. Formal malnutrition classification and longitudinal body-composition analyses were outside the study’s scope. The scientifically supported conclusion is therefore descriptive: after pancreatoduodenectomy, reduced reported intake persisted among surviving follow-up participants while inflammation and liver enzyme abnormalities attenuated, biochemical and composite indices diverged, and dietary intake showed limited correspondence with circulating biomarkers.

Subject of Research: Longitudinal dietary intake and nutritional biomarkers after pancreatoduodenectomy for periampullary malignancies

Article Title: A prospective cohort study of dietary intake and clinical–nutritional biomarkers in patients with periampullary malignancies undergoing pancreatoduodenectomy in Southeast Brazil

Article References: Ribeiro, M. A., Dos Santos, J. S., da Silva Castro Perdoná, G., & Navarro, A. M. (2026). A prospective cohort study of dietary intake and clinical–nutritional biomarkers in patients with periampullary malignancies undergoing pancreatoduodenectomy in Southeast Brazil. Supportive Care in Cancer, 34(11), Article 1130. https://doi.org/10.1007/s00520-026-11357-8

Image Credits: AI Generated

DOI: 10.1007/s00520-026-11357-8

Keywords: pancreatoduodenectomy, periampullary cancer, dietary intake, malnutrition, systemic inflammation, nutritional biomarkers, pancreatic exocrine insufficiency, cancer cachexia, Brazilian health system, prospective, cohort, dietary